1. Field of the Invention
The present invention relates to in-ground swimming pools and more particularly to in-ground swimming pools which are thermally insulated from the surrounding excavation walls and to a method of constructing such a swimming pool.
2. Description of the Prior Art
A common method of constructing in-ground swimming pools is simply to make an excavation in the ground, line the excavation walls with wire mesh screen and then simply spray a fluid cementious material such as gunnite directly against the excavation sidewalls and the wire mesh screen to build up the desired pool side and bottom wall thicknesses.
A disadvantage of this method of construction is that heat from the pool water is transferred directly through the pool walls and into the cold ground. It can thus be very expensive to heat the pool water, particularly in the winter time in severe climates and where oil, gas or other expensive fuels are used as the primary source of heat energy.
Also, in cold climates rapid heat loss through the pool walls into the ground can cause the pool water to freeze in severe climates where the water is not continuously artificially heated. Furthermore, where the ground commonly freezes to a considerable depth in winter, and is subject to alternate freezing and thawing, uneven ground pressures on the pool walls can cause them to crack.
Accordingly, there is a need for providing a means for insulating the walls of in-ground swimming pools from ground temperature extremes.